xine, ppc and illegal instructions

[Bill Fink]

Some further investigation on my part and a question for Franz Sirl:

I updated to the latest Paulus rsync kernel (2.4.3-pre8) and the
latest gcc (2.95.3-2v) and 2.1 glibc (glibc-2.1.3-15g) from Franz,
but unfortunately none of this helps.  xine 0.4.01 still gets
illegal instructions (sometimes it gets a segmentation fault
instead).  No core dump is produced and it runs basically OK
when run under control of gdb, so it makes tracking down the
problem very difficult.

>From debug printout, it appears that it is dying in a call to dlopen,
which is in libdl, which is part of glibc.  Here's the tail end of an
strace of a xine run:

open("/usr/local/install/xine-0.4.01/lib/xine/plugins", O_RDONLY|O_NONBLOCK|O_DI
RECTORY) = 7
fstat(7, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0
fcntl(7, F_SETFD, FD_CLOEXEC)           = 0
lseek(7, 0, SEEK_CUR)                   = 0
getdents(7, /* 12 entries */, 2980)     = 284
open("/usr/local/install/xine-0.4.01/lib/xine/plugins/input_file.so", O_RDONLY)
= 8
fstat(8, {st_mode=S_IFREG|0755, st_size=17054, ...}) = 0
read(8, "\177ELF\1\2\1\0\0\0\0\0\0\0\0\0\0\3\0\24\0\0\0\1\0\0\t"..., 4096) = 409
6
mmap(0xfa28000, 70000, PROT_READ|PROT_EXEC, MAP_PRIVATE, 8, 0) = 0xfa28000
mprotect(0xfa29000, 65904, PROT_NONE)   = 0
mmap(0xfa38000, 8192, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_FIXED, 8,
0) = 0xfa38000
close(8)                                = 0
mprotect(0xfa28000, 4096, PROT_READ|PROT_WRITE) = 0
mprotect(0xfa28000, 4096, PROT_READ|PROT_EXEC) = 0
--- SIGILL (Illegal instruction) ---
+++ killed by SIGILL +++

Given that the last system call was an mprotect, I searched the archives
and discovered that Olaf Hering reported a problem with mprotect on
January 23 on the linuxppc-dev list, see:

http://lists.linuxppc.org/listarcs/linuxppc-dev/200101/msg00324.html

Olaf provided a patch to fix the problem, which I wasn't totally clear
exactly what it was against, but I'm assuming it was glibc (I've never
looked at the glibc source).  Assuming it was a glibc patch, it wouldn't
be in the glibc-2.1.3-15g I downloaded since that was dated January 14.

Now my question for Franz.  Do you think the problem/patch reported
by Olaf is likely related to the apparent dlopen/mprotect problem I'm
having with the 0.4.01 version of xine (note the 0.3.7 version works
fine)?  Or could it possibly be hardware related?  I'm running on a
G4 which has Altivec, while Henry's system is a G3 IIRC, which I believe
doesn't have Altivec (or some other hardware difference).

I've pulled down the source for glibc-2.1.3-15g, but before I actually
try rebuilding it on my system (with or without Olaf's patch), I'd
appreciate some expert advice about whether it's worth the effort or
likely to have any effect.

						-Thanks

						-Bill


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